{"id":{"repo_id":"woods-hole","oai_identifier":"oai:darchive.mblwhoilibrary.org:1912/72183"},"canonical_url":"https://search.dev.ndltd.org/etd/woods-hole/oai:darchive.mblwhoilibrary.org:1912/72183","repository":{"repo_id":"woods-hole","name":"Woods Hole Oceanographic Institute","base_url":"https://darchive.mblwhoilibrary.org/server/oai/request"},"display":{"title":"Microbial responses to environmental forcing and implications for trophic transfer through the lens of lipidomics","abstract":"Phytoplankton lipids are critical molecules in the marine environment, responsive to a variety of environmental drivers, and are important stores of chemical energy within the ecosystem. Through the lens of lipidomics, I explored phytoplankton responses to nutrients in the North Pacific Subtropical Gyre (NPSG), and to light in the western Antarctic Peninsula (WAP). In the NPSG, I utilized lipid biomarkers to differentiate between cyanobacterial and eukaryotic signs of stress, in response to the passage of mesoscale eddies and their subsequent impact on ocean biogeochemistry. Lipidomic analysis of sediment trap material showed the export of particulate organic carbon (POC) enriched in the energy storage molecule, triacyglyceride (TAG), from the cyclonic eddy despite similar total fluxes of POC from both eddy systems (cyclone and anticyclone). This finding highlights the importance of a molecular understanding of the ecosystem and provides insight into the mechanism by which eddies cause increased energy export. Along the WAP, I demonstrate that lipids, and in particular TAG, are sensitive to the depth of the mixed layer, and by proxy, light availability within the water column. Shallow mixed layers have much higher average concentrations of lipid, which is critical for filter feeding krill, the primary link between the base of the food web and higher trophic levels in this ecosystem. Finally, I examine the energy derived from lipids in the diets of two higher order predators along the WAP: Adelie and gentoo penguins. I aimed to determine if differences in broad population trends can be explained by variable dietary quality delivered to penguin chicks. I found that there was similar delivery of dietary energy between species and metapopulations of penguins near Palmer Station on Anvers Island, Antarctica. However, I found that fish in diets were significantly enriched in TAG (compared to krill-based diets), and that fish were found exclusively in gentoo penguins. Populations of gentoo penguins near Palmer Station have increased exponentially in the last several decades while populations of Adelie penguins in this region have decreased drastically during the same period. Though fish in diets were observed infrequently, these energy rich deliveries to gentoo penguin chicks suggests that this species may have a competitive advantage, in addition to other species-specific differences. In total, the three chapters of this thesis explore the utility of lipids to examine complex ecosystems and make meaningful insights to the cycling of chemical energy within the marine environment.","abstract_html":"Phytoplankton lipids are critical molecules in the marine environment, responsive to a variety of environmental drivers, and are important stores of chemical energy within the ecosystem. Through the lens of lipidomics, I explored phytoplankton responses to nutrients in the North Pacific Subtropical Gyre (NPSG), and to light in the western Antarctic Peninsula (WAP). In the NPSG, I utilized lipid biomarkers to differentiate between cyanobacterial and eukaryotic signs of stress, in response to the passage of mesoscale eddies and their subsequent impact on ocean biogeochemistry. Lipidomic analysis of sediment trap material showed the export of particulate organic carbon (POC) enriched in the energy storage molecule, triacyglyceride (TAG), from the cyclonic eddy despite similar total fluxes of POC from both eddy systems (cyclone and anticyclone). This finding highlights the importance of a molecular understanding of the ecosystem and provides insight into the mechanism by which eddies cause increased energy export. Along the WAP, I demonstrate that lipids, and in particular TAG, are sensitive to the depth of the mixed layer, and by proxy, light availability within the water column. Shallow mixed layers have much higher average concentrations of lipid, which is critical for filter feeding krill, the primary link between the base of the food web and higher trophic levels in this ecosystem. Finally, I examine the energy derived from lipids in the diets of two higher order predators along the WAP: Adelie and gentoo penguins. I aimed to determine if differences in broad population trends can be explained by variable dietary quality delivered to penguin chicks. I found that there was similar delivery of dietary energy between species and metapopulations of penguins near Palmer Station on Anvers Island, Antarctica. However, I found that fish in diets were significantly enriched in TAG (compared to krill-based diets), and that fish were found exclusively in gentoo penguins. Populations of gentoo penguins near Palmer Station have increased exponentially in the last several decades while populations of Adelie penguins in this region have decreased drastically during the same period. Though fish in diets were observed infrequently, these energy rich deliveries to gentoo penguin chicks suggests that this species may have a competitive advantage, in addition to other species-specific differences. In total, the three chapters of this thesis explore the utility of lipids to examine complex ecosystems and make meaningful insights to the cycling of chemical energy within the marine environment.","abstract_has_math":false,"creators":["Bent, Shavonna M."],"institution":"Massachusetts Institute of Technology and Woods Hole Oceanographic Institution","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Van Mooy, Benjamin A. S."],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-09","date_published":"2025-09","updated_at":"2026-07-27T22:05:21Z","subjects":["Lipidomics","Trophic transfer","Energy cycling"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.1575/1912/72183"],"render_values":[{"text":"10.1575/1912/72183","href":"https://doi.org/10.1575/1912/72183","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/1912/72183","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Van Mooy, Benjamin A. 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Through the lens of lipidomics, I explored phytoplankton responses to nutrients in the North Pacific Subtropical Gyre (NPSG), and to light in the western Antarctic Peninsula (WAP). In the NPSG, I utilized lipid biomarkers to differentiate between cyanobacterial and eukaryotic signs of stress, in response to the passage of mesoscale eddies and their subsequent impact on ocean biogeochemistry. Lipidomic analysis of sediment trap material showed the export of particulate organic carbon (POC) enriched in the energy storage molecule, triacyglyceride (TAG), from the cyclonic eddy despite similar total fluxes of POC from both eddy systems (cyclone and anticyclone). This finding highlights the importance of a molecular understanding of the ecosystem and provides insight into the mechanism by which eddies cause increased energy export. Along the WAP, I demonstrate that lipids, and in particular TAG, are sensitive to the depth of the mixed layer, and by proxy, light availability within the water column. Shallow mixed layers have much higher average concentrations of lipid, which is critical for filter feeding krill, the primary link between the base of the food web and higher trophic levels in this ecosystem. Finally, I examine the energy derived from lipids in the diets of two higher order predators along the WAP: Adelie and gentoo penguins. I aimed to determine if differences in broad population trends can be explained by variable dietary quality delivered to penguin chicks. I found that there was similar delivery of dietary energy between species and metapopulations of penguins near Palmer Station on Anvers Island, Antarctica. However, I found that fish in diets were significantly enriched in TAG (compared to krill-based diets), and that fish were found exclusively in gentoo penguins. Populations of gentoo penguins near Palmer Station have increased exponentially in the last several decades while populations of Adelie penguins in this region have decreased drastically during the same period. Though fish in diets were observed infrequently, these energy rich deliveries to gentoo penguin chicks suggests that this species may have a competitive advantage, in addition to other species-specific differences. In total, the three chapters of this thesis explore the utility of lipids to examine complex ecosystems and make meaningful insights to the cycling of chemical energy within the marine environment."]},{"key":"dc:title","label":"Title","values":["Microbial responses to environmental forcing and implications for trophic transfer through the lens of lipidomics"]}]}],"canonical_facts":{"dc:contributor.advisor":["Van Mooy, Benjamin A. S."],"dc:creator":["Bent, Shavonna M."],"dc:date.accessioned":["2025-09-03T19:23:25Z"],"dc:date.available":["2025-09-03T19:23:25Z"],"dc:date.issued":["2025-09"],"dc:description":["Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2025."],"dc:description.abstract":["Phytoplankton lipids are critical molecules in the marine environment, responsive to a variety of environmental drivers, and are important stores of chemical energy within the ecosystem. Through the lens of lipidomics, I explored phytoplankton responses to nutrients in the North Pacific Subtropical Gyre (NPSG), and to light in the western Antarctic Peninsula (WAP). In the NPSG, I utilized lipid biomarkers to differentiate between cyanobacterial and eukaryotic signs of stress, in response to the passage of mesoscale eddies and their subsequent impact on ocean biogeochemistry. Lipidomic analysis of sediment trap material showed the export of particulate organic carbon (POC) enriched in the energy storage molecule, triacyglyceride (TAG), from the cyclonic eddy despite similar total fluxes of POC from both eddy systems (cyclone and anticyclone). This finding highlights the importance of a molecular understanding of the ecosystem and provides insight into the mechanism by which eddies cause increased energy export. Along the WAP, I demonstrate that lipids, and in particular TAG, are sensitive to the depth of the mixed layer, and by proxy, light availability within the water column. Shallow mixed layers have much higher average concentrations of lipid, which is critical for filter feeding krill, the primary link between the base of the food web and higher trophic levels in this ecosystem. Finally, I examine the energy derived from lipids in the diets of two higher order predators along the WAP: Adelie and gentoo penguins. I aimed to determine if differences in broad population trends can be explained by variable dietary quality delivered to penguin chicks. I found that there was similar delivery of dietary energy between species and metapopulations of penguins near Palmer Station on Anvers Island, Antarctica. However, I found that fish in diets were significantly enriched in TAG (compared to krill-based diets), and that fish were found exclusively in gentoo penguins. Populations of gentoo penguins near Palmer Station have increased exponentially in the last several decades while populations of Adelie penguins in this region have decreased drastically during the same period. Though fish in diets were observed infrequently, these energy rich deliveries to gentoo penguin chicks suggests that this species may have a competitive advantage, in addition to other species-specific differences. In total, the three chapters of this thesis explore the utility of lipids to examine complex ecosystems and make meaningful insights to the cycling of chemical energy within the marine environment."],"dc:identifier.doi":["10.1575/1912/72183"],"dc:identifier.uri":["https://hdl.handle.net/1912/72183"],"dc:publisher":["Massachusetts Institute of Technology and Woods Hole Oceanographic Institution"],"dc:subject":["Lipidomics","Trophic transfer","Energy cycling"],"dc:title":["Microbial responses to environmental forcing and implications for trophic transfer through the lens of lipidomics"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T22:05:21Z"}